A pressure sensor (or transducer) converts a fluid or gas pressure to an electrical signal as a function of the pressure imposed. These sensors are generally embodied in pressure sensor packages, and include a pressure-sensing device such as a silicon die. Such devices are typically manufactured using micro-machined or Micro-Electro-Mechanical System (MEMS) based techniques. One common technique for manufacturing a pressure sensor package is to attach a MEMS device onto a substrate, such as a ceramic or printed circuit board (PCB) substrate. Enabling circuit components such as application-specific integrated circuits (ASICs), as well as conductive bonding pads and/or electrical traces, may be mounted to or formed on the substrate for electrically connecting to the MEMS device to perform desired functions (e.g. analog to digital conversion and/or amplification).
Silicon and/or other semiconductor materials used to form the pressure sensing device, however, have coefficients of thermal expansions (CTEs) that are significantly different than those of the ceramic or PCB materials used to form the substrates. This CTE mismatch can lead to inaccurate pressure measurements due to strain placed on the sensing device resulting from environmental temperature changes. Moreover, the sensing devices are typically attached to the substrate via an adhesive. These adhesives may negatively affect sensor performance. When used in an environment which includes conductive or corrosive fluids (e.g. corrosive gasses), the sensor must be isolated from the harsh media in order to protect both the sensor as well as the electronic or electrical components attached thereto. For example, in applications which expose the sensor to harsh or corrosive media or the surrounding environment (e.g., in a fuel pressure sensing application), the adhesive can break down and ultimately fail.
Alternative pressure sensor systems and methods are desired.